The Internet has been abuzz with discussions of painful sex among our animal friends after astrophysicist Neil deGrasse Tyson mistakenly suggested in a tweet, “If there were ever a species for whom sex hurt, it surely went extinct a long time ago.” Twitter users and journalists leapt at the chance to tell one of the world’s leading astrophysicists that he was wrong about biology, and that there are a lot of members of the animal kingdom for whom the act of mating doesn’t appear to be all that pleasant.

Take the duck. Apparently, a female duck’s vagina corkscrews in the opposite direction from the corkscrew on the male’s penis, which may help her ward off unwanted advances but seems as if it could make desired sex uncomfortable for both of them. And ducks aren’t the only ones for whom copulation may be painful—to name just a few other examples, a male cat has barbs on his penis which can scrape his partner’s vagina, a male bed bug inseminates his female partner by piercing a hole in her abdomen, and female praying mantises eat their male partners when the deed is done.

It seems that humans are among the lucky ones for whom sex can feel so good that we do it more often for recreation than we do for procreation. But humans, women in particular, can feel pain during penetrative sex too. In fact, the American Congress of Obstetricians and Gynecologists notes that nearly three out of four women have felt pain during intercourse at some point during their lives. Unfortunately, sex education classes in schools often spend very little time talking about pleasure, and women especially—who frequently grow up around whispers of how much the “first time” hurts—may think they just have to put up with a little unwanted pain or discomfort during sexual experiences. (While some people can experience penile pain, often as the result of an infection, it generally is not related to sexual behavior in the same way.)

Sex should not hurt. If it does, look at that as your body’s way of sending you a signal that something is not quite right.

Before we get into specifics, however, it’s important to acknowledge some caveats.

First, it is important to note that we are talking about issues that lead to pain during consensual sexual activity. The issues involved during and after sexual assault or any kind of nonconsensual sex are very different, and we’re not going to attempt to address them here. If you suspect those circumstances might apply to you, you may want to consult your health-care provider, a mental health expert, or the Rape, Abuse & Incest National Network, which operates phone and online hotlines.

Also, this is not meant as professional medical advice. This article can give you ideas from my perspective as a sexuality educator, but it can’t give you a diagnosis. Again, only your health-care provider can do that.

With that in mind, there are many possible reasons that sex could be less than fun.

It Could Be Desire

Sex is a physical activity, to be sure, but there is a big mental component as well. Your state of mind matters. If you feel guilty, embarrassed, afraid, or even just distracted by what’s going on in the rest of your life, you might not be able to relax and become aroused. Stress and exhaustion can also get in the way of arousal, as can relationship issues, including an unequal interest in sex.

Painful sex can result from any one of these emotional factors, or a combination thereof. Take a minute to try and figure out if anything was bothering you before or during sex, and what you might be able to change so that this doesn’t happen again. It’s always good to start by talking to your partner and seeing if you can figure it out together. If the issue is ongoing, you might consider talking to a mental health expert or a sex therapist.

It Could Be Technique

No one wants to be told that they’re “doing it wrong,” and, of course, there is no right or wrong way to “do it.” That said, vulvas and vaginas are sensitive, and it is possible for them to be touched in a way that feels, well, not great. Every person is different: A technique that may make one partner feel fantastic may just be irritating to another. The same goes for sexual positions—what one person likes may make another one uncomfortable.

Here, communication is important. Give your partner some ideas and advice. Subtle clues like moaning when they get it right are great, but you may have to be more directive. It’s okay to ask someone to speed up, slow down, or move a little to the left. Be gentle and funny if you think that will help, but don’t be afraid to say what you like.

Of course, in order to do this, you have to know what you like. If your partner is game, this can be a fun team project, but spending some quality time figuring it out on your own (i.e., masturbating) can also be very useful.

It Could Be Lubrication (Or a Lack Thereof)

Blood rushes to the vagina upon arousal in a process called vasocongestion, which in turn causes the vagina to produce lubrication. This wetness helps protect against chafing and irritation when the vulva is touched or the vagina is penetrated. Without sufficient lubrication, sexual activity can be uncomfortable.

It can be helpful to figure out why there isn’t enough lubrication. Sometimes it’s because you haven’t gotten turned on enough, and spending just a little more time on foreplay could be all that’s necessary. It could also be the result of hormone changes—dryness is common in women who are going through or have gone through menopause, for instance—or certain medications. Or it could just be the natural state of your body; some people just produce less lubrication than others.

Regardless of the cause, dryness issues can be fixed by using lubricants. The truth is almost everyone can benefit from a little extra lube. A quick trip to the pharmacy will show just how many options there are when it comes to lube—from the tingly to the flavored to the vegan. Try one or try them all.

Just a few quick notes: If you’re using condoms for birth control or the prevention of sexually transmitted infections (STIs), avoid oil-based lubes because oil breaks down latex—intead, use water-based or silicone-based lubes. Also, if you’re using sex toys, you may also want stick to water-based lubes, because silicone can cause some of them to deteriorate. Read the label of whatever lube you choose; it should let you know what is and isn’t compatible.

It Could Be Medical

There are also a number of medical explanations for what might be behind the discomfort. The catch-all phrase for things that cause inflammation of the vagina—and the itching, burning, and pain during sex that goes with it—is vaginitis. STIs cause vaginitis, but so do other things like yeast infections. The truth is that the vagina has a pretty delicate system of naturally occurring bacterial and fungi that are usually kept in balance. When this equilibrium is disrupted—which can happen when a woman is taking an antibiotic, uses a fancy new soap, or has even just has sex—things can get uncomfortable.

Pain upon penetration can also be caused by certain gynecological problems, such as endometriosis (an inflammation of the lining of the uterus), pelvic inflammatory disease, or cysts on the ovaries. Many of these medical problems that cause pain are easily treated once diagnosed.

For some individuals, however, vulvar and vaginal pain can become chronic and may not be limited to during sex. These people are often diagnosed with vulvodynia—a term that basically means painful vulva. There are different theories about what causes this condition, and there isn’t one method that seems to work for everyone who has it. But there are treatments: Some individuals respond to certain medications that are thought to interrupt the pain signals the body is sending, and others do well with physical therapy and biofeedback.

The purpose here is not to give an exhaustive list of conditions that lead to painful sex, but to say that pain during intercourse is often a sign of an underlying medical problem. If it persists, you should get checked out.

Whatever You Do, Don’t Close Your Eyes and Think of England

In previous generations, women were taught not to expect sexual pleasure—sex was something for men to enjoy and women to endure. Thankfully, we now know enough to consider this absurd (not to mention sexist and infuriating). And yet, some vestiges of these views seem to have hung around and left some women with the impression that a little bit of pain during sex is just to be expected.

It’s not.

The basic rule is pretty simple. If your vulva or vagina itches, burns, or hurts—get it looked at by a health-care professional. If you have a bump or a sore—get it looked at by a health-care professional. If it hurts when someone touches it or if penetration is painful—go see a health-care professional. If you’ve ruled out physical ailments—consider talking to a therapist about what else might be going on. And if the pain becomes chronic—go back and tell that professional it is still hurting.

Don’t just grin and bear it.

We are not ducks, we are not bed bugs, and we are not antechinuses (a marsupial whose males have so much sex they start to bleed internally and go blind). We are human beings, and we deserve sex that is not just pain-free, but feels really good.